Astronomers Detect Four Earth-Sized Planets Orbiting The Nearest Sun-Like Star (ucsc.edu)

Tim Stephens reports via The University of California in Santa Cruz: A new study by an international team of astronomers reveals that four Earth-sized planets orbit the nearest sun-like star, tau Ceti, which is about 12 light years away and visible to the naked eye. These planets have masses as low as 1.7 Earth mass, making them among the smallest planets ever detected around nearby sun-like stars. Two of them are super-Earths located in the habitable zone of the star, meaning they could support liquid surface water. The planets were detected by observing the wobbles in the movement of tau Ceti. This required techniques sensitive enough to detect variations in the movement of the star as small as 30 centimeters per second. The outer two planets around tau Ceti are likely to be candidate habitable worlds, although a massive debris disc around the star probably reduces their habitability due to intensive bombardment by asteroids and comets.

Comments

Re:closer look

[Anonymous Coward]

I think we're still at the phase of our development where there is no point sending out interstellar probes. By the time they get there, either there is no human race left to monitor the info they send back, or we already sent out faster and better equipped probes that overtook them along the way. There is far more within our solar system that we have to study, perfecting the propulsion techniques with gradually increasing distances first.

Re:closer look

[Sique]

Going back to Paracelsus and his doctrine ("All substances are poisons; there is none which is not a poison. The right dose differentiates a poison and a remedy."), we find out, that "lethal plant" is not a good qualifier. To the contrary: Anything that's not lethal to us in a certain dose does not have any effect on us. Otherwise we could increase the effect by increasing the dose until it is lethal.

Thus we can conclude: Anything that (in a certain dose) has a lethal effect on us, might have another, maybe beneficial effect on us if dosed right. So all we need is the proof that a plant has an effect on us. And how will you do that without having a human (or a model organism like bacteria or guinea pigs instead of a human) nearby to test for the effect?